Cutting tool



De- 30, 1952 i J. H. GoDFREY ETAL 2,623,283

CUTTINGVTOOL Filed 0G12. 26, 1948 r 2 SHEETS-SHEET l JAMES H GODFREY HAROLD C. BECK Patented Dec. 30, 1952 CUTTING TOOL James H. Godfrey, Berlin, and Harold C. Peck, New Britain, Conn., assignors to The Stanley Works, New Britain, Conn., a. corporation of Connecticut Application October 26, 1948, Serial No. 56,652

(CI. {t-216) 1 Claim.

rIhis invention relates to a cutting tool primarily designed for cutting or trimming elastic, yieldable and cellular material of the general nature and characteristics of so-called foam rubber or foam latex.

Due to the readily yieldab-le and elastic nature of material lof this type, it has heretofore been difficult to cut or trim blocks or sheets of such material with saws or knives generally available for such or other purposes. Knives having unserrated edges have not been satisfactory even though the edges were very sharp and move at a relatively high rate of speed and regardless cf whether said knives have been used singly or a pair of them used while moving in opposite directions.

Further, attempts have been made to enhance the unsatisfactory cutting action of implements now available .by endeavoring to hold the material clamped, but this has not been found helpful inasmuch as the lack of rigidity inherent in the material is such that the same does not lend itself to being satisfactorily clamped or held while being out.

It is an object of this invention to provide a cutting tool, suitable for use on this class of material, wherein a pair of blades are each provided with teeth along :one edge and the blades are moved in opposite directions, whereby as the teeth of one blade are moved downward the teeth of the other blade are moved upward and such movements impart corresponding but counteracting motions in the material where it is being cut to thus maintain the material in a relatively stationary position during such cutting operations and no clamping of the material is necessary.

Other aims and objects of the invention are; to provide blades and teeth thereon of such shape that a minimum of cut particles are produced, to provide blades which are flat so as to permit inexpensive manufacturing thereof by stamping and grinding operations, to have the two blades of the same shape whereby they are interchangeable, to provide simplified positioning and guide means in the device so as to minimize the time and operations required to change or replace the blades, and to construct the guard and guide within which the blades operate in such a manner as to cooperate with the blades so as to place under tension uncut material immediately in front of the cutting teeth and thus facilitate the cutting action of the blades.

Details of these objects and aims as well as the structure comprising the invention and other objects thereof are set forth in the following 2 specification and illustrated in the accompanying drawing forming a part thereof.

In `the drawing, Fig. 1 is a vertical side elevation of a cutting device embodying the principles of the present invention, part of the device being shown in section to better illustrate details thereof.

Fig. 2 is a fragmentary front elevation showing the driving mechanism of the device when the front cover plate is removed.

Fig.` 3 is a fragmentary sectional side elevation of the lower lportion of the device shown in Fig. 1.

Fig. 4 is a sectional plan view, taken on the line 4-4 of Fig. 1, and illustrated in a scale larger than that shown in Figure 1. l

Fig. 5 is a perspective view of one of the crossheads shown in Figs. l and 2.

Fig. 6 is .a perspective view of one of the blades used in the device.

Referring to the drawings, and particularly Fig. 1, a-housing Il] encloses an electric motor of a conventional type, details of which are not believed necessary in the present description. A handle I2 is connected to the housing I 0, said handle having connected thereto a power cord or conduit I4 by which current is supplied to the motor within the housing I0. The handle also preferably includes a switch I6 by means of which iiow of current to the motor is controlled.

Secured to the forward end of the housing I0 is a driving head I8 within which hereinafter described driving mechanism is enclosed. Head I8 is provided with a substantially flat front face 20 to which front cover 22 is secured by any suitable means such as a plurality of screws 20. The lower portion 25 of the head I8 is provided with a vertical guideway 23 which is U-shaped in cross section, said guideway being yclosed by the lower portion of the cover 22. Said guideway is preferably substantially rectangular in cross section and is for purposes to be described.

Projecting from the forward end of the motor referred to above is a worm 30 which drives a worm wheel 32 mounted on transverse shaft 34 which is supported at its opposite ends: within suitable iopenings in the side walls of the upper portion of the head I.

Fixed to opposite sides of the worm wheel 32 are a pair of eccentrics B which are disposed at to each other. The eccentrics 36 individually drive connecting rods 38 which are clearly shown in Figs. 1 and 2. Said connecting rods are shaped so as to accommodate the worm therebetween as seen in Fig. 2.

lthe lower end of the member All.

the rearward portion of the lower end of the l Disposed within the guideway 28 is a pair of vertically disposed cross-heads Il@ and 42. The upper ends of said cross-heads are connected to the connecting rods 33 by suitable pins 43 and, as will be obvious from the drawings, as the worm gear 32 is rotated by worm 30 the connecting rodswill be'actuated to reciprocate'the crossheadszlll and t2 in vertical but opposite parallel directions. The cross-heads 4) and 42 are shaped so as to closely but slidably fit within the rectangular guideway 28 and the lower portion of the cover 22, when connected to driving head I8, closely confines the cross-heads for slidable movement within said guideway 28.

Depending from and connected tothe lower end surface of the lower portion 26 on head IS is a member 4d provided with a vertically extending elongated guide channel llt. In cross section, as viewed particularly in Fig. Ajit will be seen that the guide channel la renders the member lie U-shaped. Preferably the member lili is provided at its upper end with a horizontally extending flange l5 'which is detachably connected to said lower end surface of portion -26 by suitable screws t5.

Secured to the lower end of the mem-ber M is a guide foot or shoe d8 having an opening 5G therein extending vertically therethrough for purpose of receiving the lower end of member 4:2.. Said opening also includesa pair of shoulders 52 which engage the front edges'of thefside portionsoi the member d4 that denne' the guide channel de, Said opening also includes Ianv extension opening 5d extending forwardlyfor .purposes to be described.

Shoe 43 is also provided with a threadedopening in its rearward portion to receiveaset screw 5S which is arranged to be tightened against the rearward surface of the lower end of the member dd, as shown in Fig. 3, to tighten the shoulders 52 in the shoe i8 against thefor- Vward edges of the member M. By this means the shoe '48 is iirmly but detachably secured to If desired,

member le may be provided -with a notch 58 `to receive and properlfT position the set screw 5S and shoe 43 relative to member iid.

Mounted within guide channel d and also extending into the opening 50 and guideway 28 is a pairof blades G one of which isshown to advantage in Fig. 6. Said blades are ilat elongated strip memberswhich may be formed 'by cutting and stamping operation from stripstock. One edge of each blade is provided with a row of `cutting teeth 62, Vall of which are placed so .as to extend-at an angle toward one end of thefblade, The toothed edge of each bladeis 'also beveled inwardly from one flat surface of the blade toward the other, whereby the teeth areV pointedat their outer ends due to the beveled surface 6&3.

In operation, the lblades are disposed with `their flat, unbeveled surfaces in slidable engagement with each other and the teeth of each, blade juxtapositioned.

'No set is provided in the teeth and they may ybe readily sharpened by grinding the 'beveled surfaces Sil. Further, in the preferred embodi- `ment of the invention, the pitch of the teeth is lIO longitudinally aligned slots G6 which are primai-ily for purposes of positioning and guiding the blades during the operation thereof. Extending inwardly from the rearward 01 nontcothed edge of each blade, adjacent each end thereof, is a notch-like opening 6&3 for purposes to be described.

'The crossheads "i0 and 42 are each provided adjacent their lower ends with a fiat, shallow 'recess Hl which accommodates one of the upper ends of the two blades 6!! when mounted within the device. The cross-heads are also both provided with 1 positioning pins or projections 14. Each projection le is received within the slot 66 in the upper end of one of the blades received within said ilat recess l0 in the cross-head for the purpose of properly positioning the blades relative to the cross-heads in a transverse direction.

Each cross-head is also provided with a lug 'I6 Awhich is received within the opening `'in'the ,in which extends between suitable openings formed in the lower portion of the member vlili. Pin T8 thus maintains the lower ends ofthe blades 6) in vertical longitudinal alignment `and cooperates with the projections 'i4 on the crossheads which serve to maintain the upperends of the blades in similar alignment.

As will be seen from Figs. 1 and 3, and particularly the latter, when the two blades 6i) are mounted in operative position the teeth' 62 of `one blade will be pointed upward, for example, and the teeth of the other blade will be pointed downward relative to the vertical direction of movement of said blades. Therefore, as the upward pointed teeth move upward into the material being cut, the downward pointed teethon ,the other blade will move downward and counteract any upward movement imparted to the material by the teeth on the rst mentioned blade. Such ccunteraction serves to maintain the material'being cut in any position in which it reposesrand no clamping or holding of the material is necessary while it is being cut.

It will be noted further that the forwardend 80 of the guide shoe A8 is curved and tapered forwardly so that the shoe readily travels under the lower surface of the material being cut. Further, as mentioned hereinabove, the opening 59 in the shoe t has a forward extension 54 which accommodates the lower ends of the toothed edges of the blades 6i), whereby the teeth on said blades do not contact the shoe 58 during operation of the blades.

Inasmuch as the blades Et are identicaLthey vmay be interchanged with each other and ionly one style of blade need be maintained in stock for replacement purposes. Regardless of vthe side in the guide channel 46 within whichv aiblade is disposed, the end slots 66 are both use difor purposes of receiving either the projections 'M .onone of the cross-heads 42er the guidepin 1,8 l.projecting.through the lowerend of 'thegguide channel 5. Only one of the notch-like openings 83 is used for purposes of receiving the lug 79 on one of the cross-heads and the other opening 63 is not used under these circumstances. However, the additional opening 88 is required when the blade is used in the other side of the guide channel from that disclosed above.

It will be apparent that when it is desired to shift a blade from its operative position within one side of the guide channel to the operative position of the blade in the other side of the channel, the blade is merely rotated 180 in a plane transverse to the plane of the blade when within the channel. Such rotation will place in the upper portion of the guide channel the opening 68 which was originally in the lower portion thereof. The opening 63 which is uppermost in the blade when mounted in the guide channel is the one which receives the lug on one of the cross-heads.

Replacement or interchanging of the blades is readily accomplished merely by removing the guide shoe 48 from the lower end of the-member ed, removing front cover 22 from the driving head it, and sliding the cross-heads di) and 42 forwardly out of the guideway 28 so that the upper ends of the blades may be disconnected from the I projections 'ill and lugs 18 on the cross-heads.

The blades may then be shifted or replaced and the newly positioned blades as well as the crossheads are then re-positioned within the guide channel 46 and guideway 28. The front cover 22 and the guide shoe 49 are then remounted in their operative positions.

Another advantageous feature of the invention comprises the provision of beveled surfaces 82 on the forward edges of the side portions of the member 44 which define the guide channel 4S. As is clearly evident from Fig. l particularly, the beveled surfacesl 82 extend from immediately above the upper surface of the guide shoe 28 to near the upper end of the member 44. Said beveled surfaces extend rearwardly and `outwardly from the free edges of the side portions defining the guide channel 49 andthe angle at which said beveled surfaces are disposed blend with the exposed forward toothed edges of the blades 60, as is readily shown in Fig. 4. The beveled surfaces 82 facilitate the cutting function of the teeth of the blades by camming apart the cut surfaces of the incision made in the material and thus place under tension the uncut material immediately in front of the teeth of the blades.

While the invention has been illustrated and described in its preferred embodiment and has included certain details, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways, falling within the scope of the invention as claimed.

What We claim is:

A device for cutting elastic yieldable material comprising in combination, a pair of blades having opposi-tely directed cutting teeth, the blades being arranged in a side-by-side relation with `the inner confronting sides of the teeth substantially co-planar and the outer sides of the teeth tapered, guide means embracing the sides of the blades and tapering outwardly from said blades adjacent said teeth, and means for reciprocating said blades in opposite directions relative to said guide means.

JAlWES H. GODFREY. HAROLD C. PECK.

REFERENCES CITED ri'he following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 139,426 Scholfeld May 27, 1873 311,170 Beurmann Jan. 27, 1885 353,552 Galster Nov. 30, 1886 386,183 Brooks Jury 17, 183s 431,998 Salisbury July 8, 1890 460,677 Christy Oct. 6, 1891 703,036 Baird June 24, 1902 850,928 Gury Apr'. 23, 1907 1,136,842 Siegal Apr'. 20, 1915 1,254,563 Anderson Jan. 22, 1918 1,492,134 Kyle Apr. 29, 1924 1,690,808 Appelbaum Nov. 6, 1928 1,726,863 Singer Sept. 3, 1929 1,917,889 Jacques July 11, 1933 2,305,465 Bangser Dec. 15, 1942 

